Reference may be made to the following U.S. patents of interest: U.S. Pat. Nos. 3,895,690; 3,171,510; 3,135,355; 2,990,916; and 2,684,733.
The aforementioned U.S. Pat. Nos. 3,895,690 and 2,990,916 describe lubricating apparatus for trolley wheels on a conveyor system which is constrained to move in a linear path by means of a trolley track or other guide. These patents illustrate a lubricator coupling which is placed into engagement with a lubricant fitting and constrained to follow the same linear path as the trolley wheel. During the dwell time, defined as the time during which the lubricator coupling is engaged with the trolley wheel lubricant fitting, a measured quantity of lubricant is supplied.
While such lubricating apparatus are satisfactory for the purposes intended, they lack the ability to satisfactorily engage and maintain engagement for a sufficient dwell time where the lubricant fitting is on a conveyor which may not move in a confined linear path. As an example, conveyors utilized in traveling water screens such as those found in electrical power generating stations and steel mills, and foundry chains, are not constrained to move in a linear path. Such traveling water screen conveyors and foundry chain conveyors move in various non-linear paths depending on respective factors such as load variation, speed, water pressure, wind loading, etc. While the above-referenced patents proposed lubricating apparatus which is able to follow a conveyor over a reasonably long path and provide sufficient lubricating dwell time, the apparatus is limited to use with conveyors which travel in a confined linear path.
In addition, there is presently available a lubricator apparatus incorporating a telescoping lubricating nozzle which extends to engage and lock with a moving lubricant fitting on a non-confined conveyor. This unit includes a double pivot and rotation action to enable the entire unit to sway and move with the conveyor during slightly non-linear conveyor movements. Although such a device is able to flex freely in several directions, it is not able to achieve the dwell time necessary to inject lubricant except at low conveyor speeds. Furthermore, it has been found that while the entire unit is able to flex freely in several directions, the lubricating coupler is fixed in position and therefore cannot maintain engagement over a sufficient dwell time except for very small deviations of the conveyor from a linear path and only over a small distance.
Accordingly, it is desired to provide an automatic lubricator which can reliably engage and maintain engagement for a sufficient dwell time for use with conveyors moving in various non-linear paths.